The California Department of Toxic Substances Control cited FedEx in a civil complaint noting more than 1,500 violations at 31 FedEx terminals and the company's hubs in Sacramento, Los Angeles and San Bernardino counties.

State officials say that FedEx transported damaged and leaking packages of hazardous substances through hubs that weren't authorized for such materials. Officials accused FedEx of shipping packages of acids, solvents, insecticides, batteries and other flammable toxic or corrosive materials without the proper labels, registration and manifest.

FedEx spokeswoman Katie Wassmer issued a statement on behalf of the global shipping firm in response, denying the state's claims.

"Safety is essential to our business and FedEx complies with all applicable local, state and federal reporting requirements," she said

The California Attorney General's office filed the 15-page civil complaint in the Sacramento County court on behalf of the Department of Toxic Substances Control.

Paul Kewin, who heads the department's enforcement division, said state officials negotiated with FedEx for more than a year to change the company's practices, before deciding it was time to file the complaint in court.

"What FedEx was doing was outside the bounds of California law," Kewin said. "We believe that every act that's outside the law increase the likelihood of potential exposures to workers and the public."